1. Field of the Invention
This invention relates to a kingpin assembly for a steering axle and, more particularly, to such a kingpin assembly which includes an intermediate section thereof having a helically splined outer surface adapted to produce an interference fit with a splined mounting bore through the end of an inner axle member of the axle to rigidly retain the kingpin in position as a steering knuckle is pivotally mounted thereon.
2. Description of the Prior Art
Steering axles are well known in the prior art to include an inner axle member with a kingpin rigidly mounted in a mounting bore at each end thereof. Upper and lower sections of the kingpin are adapted to pivotally support a steering knuckle having rigid upper and lower yoke arms. A spindle extending outwardly from the steering knuckle is adapted to rotatably support a vehicle wheel of the steering axle.
It is of primary concern in some kingpin assemblies that the kingpin be rigidly secured within the mounting bore at the end of the inner axle member to insure that pivotal movement between the members is limited to the upper and lower yoke arms as they rotate about the upper and lower sections of the kingpin. Various methods are employed for rigidly providing kingpin assemblies of this type such as those generally disclosed in U.S. Pat. Nos. 1,637,089; 2,512,881; 2,916,295; 3,294,413 and 3,915,469.
Typically, the kingpin is rigidly retained within the mounting bore of the inner axle member by a slot and key configuration requiring a number of additional parts and additional steps in the manufacturing operation. Although these methods of insuring the rigid mounting of the kingpin have generally been satisfactory, there is a continuing need to decrease the overall expenses of manufacture while still providing a reliable kingpin assembly.